OpenSSH is the best tool for remote login using the SSH protocol. It encrypts all traffic to prevent eavesdropping, connection hijacking and other attacks. OpenSSH also offers a wide range of secure tunneling options, many authentication methods, and advanced configuration options. Remote operations can be done with ssh and scp. Key management is done with ssh–add, ssh–keysign, ssh–keyscan and ssh–keygen. The service side includes sshd and sftp server, as well as ssh–agent. OpenSSH was developed by a few OpenBSD developers and made freely available under a BSD license. OpenSSH can be integrated into many commercial products. However, very few companies support OpenSSH funding. OpenSSH Foundation can accept contributions. All operating systems should include support for SSH protocol because telnet, rlogin and other insecure protocols are not secure. SSH protocol can be used in two different versions, SSH 1 or SSH 2.